Electrical resistance element and process of making the same.



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OR PLASTIG UNITED STATES PATENT OFFICE- MERRIT H. RICE, OF NEW ROCHELLE, NEW YORK, ASSIGNOR T0 NATIONAL ELECTRIC UTILITIES CORPORATION, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

ELECTRICAL RESISTANCE ELEMENT AND PROCESS OF MAKING THE SAME.

80 Drawing.

To all whom it may comem:

Be it known that I, Mnnm'r H. RICE, a citizen of the United States, residing at New Rochelle, in the county of Westchester and State of New York, have invented new and useful Improvements in Electrical Resistance Elements and Processes of Making the Same, of which the following is a specification.

This invention relates to electrical resistance elements and rocesses for making the same and has for its object the production of a composite electrical resistance element consisting of a base and an envelop or covering fused thereto or united therewith, preferably of a material or composition which is hard, melts only at high temperatures, cannot be easily broken, 1s a non-conductor of electricity, and adapted fully to protect the base against disintegration. The base of the. electrical resistance element may be of any suitable material, such as, for example, carbon or a substance comprising carbon as a constituent. The coatin or 1ts ingredients may vary withinco'fisi e'rable limits provided they are such as to fuse or unite with the base and thus afford a' coating of the Bli'thick paste of about character described. The particular ingredients of the coating which are preferably used comprise a material, as, for example, glraphite, a binder, as, for example, French c ahd an agent for their manipulation application, as, for example, water or ggluble glass. These or their equivalents are made to unite with the base, preferably in an oil flame, so as to form on the base the coating or envelop. The. whole affords a composite electrical resistance element of great utility.

In order that the invention may more readily be practised, it is hereinafter described in ater detail usin for purposes of illustratlon carbon as the ase, graphite as the ingredient ofthe coating which may be referred to as the material, French clay glass as the agent used in mampulating and applying these ingredients, and a furnace burnin crude oil as the source of heat.

To orm such a coating for an electrical resistance element, five parts of} a bite and two-parts of French cla are mixed t ogether with enough soluble [ass to form a the cons fincy. of mo- Specification of Letters rum.

Patented July 10, 1917.

lasses. A layer of this paste is spread upon the carbon and allowed to dry. The pastecovered carbon is then placed in a furnace preferably burning crude oil-andthe oil flame preferably directed against the electrode for several hours. The result of this is that the coating becomes fused or united with and forms an integral covering for the carbon. The composite electrical resistance element thus formed is removed from the furnace, cooled, and is then ready for use. The coating made of the in edients specified and thus fused or unite with the electrical resistance element proper is extremely hard, a non-conductor of electricity, melts only at extremely high temperatures, and can not be easily broken. Such a composite electrical resistance element is of great utility because the base is shielded from contact with the air and protected against disintegration by a. lasting, fireproof, electrical insulating covering.

Graphite, being not easily fusible, and French clay, being capable of resisting very high temperatures, are the best ingredients the be rcisults, to wit, one part of soluble glassfi i) uor-s ar two parts of Irene? 0 a1 and Eve parts of B aphiteJ owever, these proportions nee no e strictly Cross Reference- EXAMINER adhered to because they may be varied with- I out losing all the advantages of the invention. The use of a furnace burning crude oil is desirable because the petroleum flame operates to give the desired character to the coating or envelop,-by deposit or "otherwise more effectually than any other source 0 heat with which I am familiar Analyses of the coating of composite electrodes made in accordance with my process as' described indicate that the coating contains a double silicate of aluminum and soda. I have een una e to etermine w e er or not the coating also contains crystallized carbon, but I believe this to be the case.

The composite electrical resistance element of my invention may be used in all kinds of electric heating and cooking apparatus. In actual practice I have found it particularly useful in electric ranges.

What I claim is 1. An electrical resistance element comprising a carbon base having a fused-on integral rotective coating consisting of a double silicate of alumina and soda.

2. The process of manufacturing electrical resistance elements, comprising coating a carbon base with a coating contaming graphite and clay, and fusing said coating to said ass.

3. The process of manufacturing electrical resistance elements, comprisin coating 9. base with a mixture of graphite, clay and rater-glass, and fusing said coating to said ass.

4. The process of manufacturing electrical resistance elements, comprising coating a carbon base with a mixture of graphite, clay and water-glass in about the following pro portions: one part water-glass, two parts rench clay, five parts graphite, and fusing said coating to said base.

5. The proces of manufacturing electrical resistance elements comprising coatin a base with a composition containing aplnte, clay and water glass in about the ollowing proportions :1 part water glass, 2 parts clay and 5 parts graphite, subjecting the same to heat to fuse the composition to the base, and cooling the resultant product.

6. The process of manufacturing electrical resistance elements comprising coating; base with a composition which will thereto when heated, subjecting the coated basetodirectactionofaflamefromanoil masses furnace to form a composite resistance element consisting of a base and;v integral coating, and cooling the composite product thus formed.-,

7. Thb process of manufacturing electrical resistance elements Y comprising coating a base with a composition containing graphite and clay subjecting the coated base to 'rect action of a flame from an oil furnace to form a composite resistance element consistin of the base and inte coating, and coo g the product thus ormed.

8. The process of manufacturing electrical resistance elements comprising coating a base with a coating material and a binder, subjecting the coated base to direct action of a flame from an oil furnace to form a com osite resistance element consistin of the ase and integral coating, and coo the product thus formed.

9. The process of manufacturing electrical resistance elements comprising coating a base with a composition containing. graphite clay and soluble glass, subjecting the coated base to direct action of a flame from an oil furnace to form a composite resistance element consisting of the base and into 1 coatiigg, and cooling the -product us form In testimony whereof, I have hereunto set my hand in the presence of witnesses.

MERRIT H. RICE. Witnewes:

E. C. VAN Guns, Annx T. Gm'immne, 

